Road pavers are in practice used to install new road surfaces by use of a screed arranged thereon. The paving material for this is taken from a material hopper of the road paver which is in the installation direction arranged at the front of the road paver. The paving material is via a material conveying device transported from the material hopper to the rear to the screed, spread out in front of the latter by use of a distribution auger and finally installed beneath the screed by use of heated compaction units to form the new road surface.
In order to be able to install a flat road pavement on the road bed on which the road paver moves, the screed is attached to the chassis of the road paver by way of height-adjustable screed beams. Leveling of the screed can be controlled by a control unit of the road paver. Leveling the screed there depends on the surface condition of the road bed or on the target thickness of the road pavement to be installed.
It is known that a measuring bar device is for leveling the screed of a road paver used in practice laterally along the road paver for supporting a plurality of height measuring sensors above the road bed as well as behind the screed. Leveling the screed can then be effected based on the readings of the height measuring sensors.
For example, DE 602 26 237 T2 shows a measuring bar device with beams arranged one above the other which can be telescoped along the road paver in order to position sensors for height measurement on the side of the road paver above the road bed. The respective telescopic bar segments can be attached at a desired location by way of anchors provided thereon. In addition, the respective height positions of the sensors can be adjusted. The drawback of this is that the telescopic measuring bars add large weight and can therefore only be used on special types of road pavers. In addition, several people are needed for mounting the measuring bar device on or for removing it from the road paver. In addition, the options with regard to the mounting height of the sensors are limited.
U.S. Pat. No. 5,975,473 A discloses a measuring bar device mounted laterally on a road paver. The measuring bar device is by articulated pivot arms attached to a screed beam of the road paver. Furthermore, the measuring bar device comprises a measuring bar supported laterally along the road paver and having a center bar as well as extension bars attached to the ends thereof. Attached to the center bar and to the extension bar are respective height measuring sensors. The respective extension bars can be pivoted inwardly relative to the center bar in the horizontal plane so that the sensor at the rear of the road paver attached to the rear extension bar can be positioned above the newly installed pavement layer behind the screed. In this measuring bar device, the respective segments connected to each other in an articulated manner are coupled by way of threaded screw connections. Assembly is therefore very complex and time-consuming. In addition, different clamping forces act upon the respective threaded screw connections, which ultimately depends on the operator adjusting the support device. This makes mounting and adjustment of the support device more difficult and does not make it easy to assemble for everyone. In addition, it is not uncommon for such a complex measuring bar device that individual components, in particular, loose screw levers, screws and clamps are lost at the construction site. Finally, the options for adjusting respective height positions for the sensors are in this measuring bar device limited.
DE 691 26 017 T2 discloses a road paver with a measuring bar attached thereto which is configured to be rigid and positioned above the road bed on the side of a screed beam of the road paver. A disadvantage of this is that the measuring bar can due to its rigid configuration be used, in particular, only on a limited number of types of road pavers.